Send notification mails for external alerts

See merge request gitlab-org/gitlab-ee!9457

Port migration fix from EE 9270

See merge request gitlab-org/gitlab-ce!25004

Resolve "Implement access controls when SSO enforcement enabled"

Closes #9413

See merge request gitlab-org/gitlab-ee!9270

docs: GitLab uses group milestones to handle issues

See merge request gitlab-org/gitlab-ce!24953

Enable fast task lists for merge requests

Closes #19745

See merge request gitlab-org/gitlab-ce!24779

Enable fast task lists for merge requests and epics

See merge request gitlab-org/gitlab-ee!9431

Add setting for first day of the week

Closes #19282 and #2105

See merge request gitlab-org/gitlab-ce!22755

EE port: add setting for first day of the week

See merge request gitlab-org/gitlab-ee!9465

Remove some racing expectations

Closes #9648

See merge request gitlab-org/gitlab-ee!9490

Use alert presenter in notification mails

See merge request gitlab-org/gitlab-ee!9423

Fixes Cluster base domain documentation

See merge request gitlab-org/gitlab-ce!25008

Uses the preferred way for introduced blocks instead of notes, on
auto devops and cluster documentation.

Also fixes some typos.

Also adds specs and fixes existing specs

Allow single tasks to be updated quickly

Also adds specs and fixes existing specs

Allow single tasks to be updated quickly

Merge branch '9446-split-geo-projectsyncworker-into-repositorysyncworker-and-wikisyncworker-option2' into 'master'

Geo: Handle repository and wiki sync separately in Geo::ProjectSyncWorker

Closes #9444, #9446, and #5348

See merge request gitlab-org/gitlab-ee!9360

Resolve "Override squash commit message"

Closes #47149

See merge request gitlab-org/gitlab-ce!24724

Resolve "Override squash commit message"

See merge request gitlab-org/gitlab-ee!9464

Fix failing test in spec/workers/post_receive_spec.rb

Closes gitlab-ee#8871

See merge request gitlab-org/gitlab-ce!24993